Stabilization of petroleum hydrocarbons



Patented ay 12, 1942 UNITE STT S orrlcs STABILIZATION OF PETROLEUM HYDBOCABBONS No Drawing 27 Claims.

This invention relates to the improvement of petroleum hydrocarbons and particularly to the stabilization of such petroleum hydrocarbons against the deleterious catalytic action of metals. and still more particularly to the treatment of petroleum lubricating oils to render them noncorrosive to metals.

It is known that various metals, and particularly copper, in contact with petroleum hydrocarbons or dissolved therein, tend to catalyze the deterioration of such petroleum hydrocarbons, accelerating the formation of gum, sludge, and corrosive products. It has been proposed to stabilize petroleum hydrocarbons against oxidation by the addition of various anti-oxidants. However, most antioxidants are relatively ineflective in the presence of catalytic metals, such as cop- Application June 14, 1939, erial No. 279,043

catalytic action of metals normally active to catalyze deterioration thereof. In particular, I have found that the addition of such compounds to viscous petroleum hydrocarbon oils, that is, those having a viscosity of at least 35 seconds Saybolt Universal at 100 F., will inhibit the deterioration and formation of corrosive products in such oil, which corrosive products would tend to corrode metals, and particularly bearing alloys of the character of cadmium-silver and copper-lead bearing alloys.

The compounds of my invention are character- .ized by the presence of the structural unit per, since such catalytic metals also accelerate the oxidation and destruction of the antioxidant, The viscous petroleum hydrocarbon oils, in particular, deteriorate to form acidic products which are frequently highly corrosive to metals and a1- loys with which they come into contact, and particularly the newer bearing alloys. The production of corrosive products is particularly notice-- able in the highly refined lubricating oils which possess very desirable characteristics in other respects.

It is an object of the present invention to provide compounds for addition to petroleum hydrocarbons to inhibit the deterioration of such hydrocarbons in the presence of catalytically active metals. Another object is to provide a method of inhibiting the deterioration and formation of corrosive products in viscous petroleum hydrocarbon oils. A further object is to provide a method of inhibiting the corrosion of alloy hearing metals of the character of cadmium-silver and copper-lead bearing alloys by petroleum lubricating oils in contact therewith. Still further objects are to provide new compositions of matter and to advance the art. Other objects will appear hereinafter.

The above and other objects may be accomplished in accorda ce with my invention, which comprises incorptfi' ating in petroleum hydrocarbons a small amount, suflicient to retard deterioration thereof, of an organic compound having an amino nitrogen atom and a divalent sulfur atom, each singly bonded to adjacent aliphatic carbon atoms, the second valence of the sulfur atom being satisfied by hydrogen or an aliphatic radicle. I have found that, when such compounds are added to the petroleum hydrocarbons, they will prevent the deterioration caused by the in which the carbon atoms are aliphatic carbon atoms. I believe that this is the effective part of the molecule which renders the compounds efiective for my purpose. The free valence of the sulfur may be satisfied by hydrogen or an aliphatic radicle and the free valences of the nitrogen may be satisfied by hydrogen, aliphatic or aromatic radicles. The compounds may contain, as substituents, sulfur, hydroxy, amino, alko y or aryloxy radicles, but should preferably be ree from aromatic rings. Amongst the compounds which I have found to be particularly effective for my purpose are:

. 1,6-hexamethylene di(beta-aminoethyl) sulfide Beta-phenylaminoethanethiol ON-DRa-C Ha-S H Beta-(N-phenyl-N-ethyl) -aminoethanethiol G L -0&0 Hz-S H fuels, furnace oils and lubricating oils, they pour-point depressants, oiliness agents, film strength improving agents, and viscosity index improving agents and, in gasoline, inthe presence of antiknock agents such as tetraethyllead. They may be employed in the pure state or in the form of mixtures or solutions. They may be employed'in'greases, cutting oils and insulating oils.

While it is preferred to incorporate the compounds directly in the petroleum hydrocarbons, effective results may also be secured by adding the components of the compounds to the hydrocarbons and then causing them to react therein to produce the compounds in situ.

In order to illustrate more clearly the preferred embodiments of my invention and the preferred modes of carrying the same into effect, the following examples are given:

Example 1 Into a solution of 0.4 mole (172 g.) of ethylenimine in 100 cc. of water was passed a slow stream of hydrogen sulfide, the reaction vessel being cooled in ice water. solution with a small amount of oily material on top. The water was removed under reduced pressure, leaving 18.3 g. of a colorless, almost odorless oil which boiled at 124-126 C. at 17 mm. This product was bis(beta-aminoethyl) sulfide,

,S(CH2CH2NH2)2, as shown by its boiling point and neutralization equivalent (calculated 120, found 123) The yield was 76% of the theory.

2 Example 2 A sealed Carius tube containing 13.9 g. (0.15 mol) of aniline and 4.5 g. (0.075 mol) of ethylene sulfide was heated for 4 hours at 130-135 C. and then for hours at 160-170 C. At the end of this time the tube was cooled in a dry ice-acetonev mixture, opened, and the contents distilled under reduced pressure. The yield of beta-phenyl aminoethanethiol, boiling at 140-143 C./12 mm., was 65% of the theoretical amount. Analysis, sulfur (found) 20.40%; (calculated) 20.91%.

Example 3 dg zosz'es; N :1.4831

Analyses indicate that it is the expected propylbeta-aminoethyl sulfide,

CHaCHzCHzSCI-IzCHzNHz obtained in 78 per cent yield.

The product was a clear- Calculated for emails: s, 26.89. Found: 26.82, 26.87. Neutralization equivalent: Calculated: 119; Found: 119.5.

Example 4 A mixture of 11 parts of ethylenimine and 18 parts of hexane-1,6-dithiol is heated in a closed vessel at C. for 23 hours. There is obtained, on distillation of the reaction product, 25 parts of an oil boiling around 200 C. at 6 mm. pressure. The product, on redistillation in an atmosphere of nitrogen, boils at 196-200 C. at 2 mm. pressure.- It is a pale yellow oil which crystallizes on standing to a solid melting at 38-40 C. Analyses.

indicate that this product is the expected 1,6-hexamethylene di- (beta-aminoethyl) sulfide, NI'I2CH2CH2S(CH2)6SCH2CH2NH2, obtained in 89 per cent yield.

Calculated for C10H24N2Sai C, 50.85; H, 10.17; S ,.27.12. Found: C. 51.02; H, 10.04; S, 26.74. Neutralization equivalent: Calculated, 236; Found, 241.

The effectiveness of the compounds of the type given was determined by a procedure similar to that described in the Analytical Edition of Industrial and Engineering Chemistry, volume 6, page 419 (1934), modified by suspending in the oil strips which had been cut from cadmiumsilver bearings and placed in such a fashion that the strips were completely immersed while the air which was bubbled through the oil washed over the metal surfaces. In this test, a volume 01300 cc. of oil was used through which washed air- Using a solvent-extracted Mid-Continent oil, having a Saybolt Universal viscosity of 63 seconds at 210 F. (an SALE-30 oil), the eflectiveness' of typical compounds included in this invention are given in the following Table I. In all of the tests; the compounds were incorporated in the oil by simple stirring and heating.

Table I Hours to Be bolt 23% 1o man/sq. in. Un wcrsal Compound i corrosion of viscosity at by weight um- 210 I. after silver 100 hours None-control B is beta-aminoethyl) 17 n6 sulfide 0. 25 222 77 Hexamethylene di(beta- 0. 25 282 74 aminoethyl) sulflde- 0. 05 122 78 Beta(phenylamino) ethanethiol 0. 25 93 82 Beta (N-phenyl-N-ethylamino) ethanethiol 0. 25 66 In the following tests, the method of evaluat1on was somewhat different but serves to show the corrosion inhibiting power of this type of compound. The method is as follows:

Fifty grams of a commercial paraflln base oil of an SAE-20 grade, to which had been added 0.5% of the compound under test, were placed in a 125 cc. Erlenmeyer flask. The flask was autobody steel, were suspended in the flask in such a fashion as to be immersed to approximately half their lengths in oil. The unit was placed in an oil bath maintained at substantially 175 C., and air which had been passed through two washing bottles of distilled water, was bubbled through the capillary tube at a rate of 2.5 to 3.0 liters per hour. The strips of cadmiumsilver and copper-lead bearing metals were removed at intervals and weighed after washing with chloroform and acetone. From the curve of loss in weight against time of exposure, it was possible to determine the time at which a mg. loss per 10 gms. of bearing metal occurred.

Example 6 Hours to 10 mg./l0 gm. loss Compound Cadmium- Coppersilver lead None-control 21 Below 20 Bis (beta-diethylaminoethyl) sulfide 30 42 Example 7 Hours to 10 mg.l10 gm. loss Compound Cadmium- Coppersilver lead None-control Below 20 Below 20 n-Propyl-(beta-aniinoethyl) sulfide v 25 Example 8 Stabilizing action on gasoline was measured by determining the efiect of an aminoethylsulfide on the induction period (Voorhees and Eisenger, S. A. E. Journal, volume 24, 584 (1929)) of a gasoline with and without the addition of copper in the form of copper oleate and in the presence of a gum inhibitor, p-benzylaminophenol.

It will be understood that the above examples 0 are illustrative only and are not intended to be limiting. Still other compounds ofmy invention which may be employed are:

Bis(beta-phenylaminoethyl) sulfide Bis(beta-cyclohexylaminoethyl) sulfide H: H: H: H:

Bis(beta-dicyclohexylaminoethyl) sulfide Bis[beta(p-hydroxyphenylamino) ethyl] sulfide HOQIf-C HrCHg-S-CHz-CHz-lf-OOH Decamethylene-di (beta-aminoethyl) sulfide HaN-CHr-CHr-Hflz-(CH:)a-CK:SCH:CHr-NH; 1,3-bis (beta-diethylaminoethylthio) propane CIHI Cz s N-CHrCHz-S-CHrCHzCIIrSCHrCH:-N

0:115 Ca Bis (propylaminoethyl) sulfide N-cm-cm-s-cnrcm-N H I n \H Beta-amino-beta'-propylamino-diethyl sulfide mN-Cm-Cm-s-sm-Cm-n Bis (o-aminocyclohexylthio) ethane Z-aminopentyl. butyl sulfide Bisi (beta-phenylamino alpha-phenyl) ethyl] sulfide (FEW l,4-bis[ (l-ethyl-Z-methylamino) ethylthio] butane c Ha-C Hn-C H-SC HTCHTC m-o Hrs-C fron -om CHr-NH-CHB HrNH-CH3 1,3 -bis[ (1-propyl-2-cyclohexylamino) ethylthio] propane c Ha-C Ht-C Hi-C H s -c H-CHz-C Hr s C 11-0 HrC 111-0113 Bisi (1-methyl-2-cyclopentylamino) ethyl] sulfide CHz-CH: CBx-CH:

HrCH; A H: H: H GET-CH:

Many other compounds will be apparent to those skilled in the art. Some of these compounds are known and the methods of preparing them are described in the literature. Others are new, for example, the compounds of Examples 3 and 4.- Examples 1, 2, 3 and 4 give illustrative methods of preparing the com- Pounds.

It will be apparent that, by my invention, I have been able to effectively stabilize petroleum hydrocarbons generally against the deleterious catalytic action ofmetals such as copper, cadmium, silver and the like. li/i'y compounds are petroleum hydrocarbon oils which comprises incorporating therein a small amount, sufllcient to retard-such corrosion and formation of corretard such corrosion and formation of corrosive products, of an organic compound having an amino nitrogen atom and a divalent sulfur atom each singly bonded to adjacent aliphatic carbon atoms in open chain configuration, the second valence of the sulfur atom being satisfied by an aliphatic radical.

particularly effective in petroleum lubricating oils for retarding the formation of products corrosive to metals, and particularly to cadmium, silver, copper, lead, and like bearing alloys under service conditions.

By the term petroleum hydrocarbons" as used herein and in the claims, I means to include the various hydrocarbons of petroleum origin such as natural oils, cracked products, polymerized products, reformed products, alkylated products, hydrogenated productsand products which have been refined in any of the usual ways as by treatment with sulfuric acid or with extraction solvents or by removal of wax, etc.

I claim:

1. The method of inhibiting the deterioration of petroleum hydrocarbons in the presence oi metals normally active to catalyze deterioration thereof, .which comprises incorporating in the petroleum hydrocarbons a small amount, sufficient to retard de rioration thereof, of an organic compound h g an amino nitrogen atom and a divalent sulfur atom each singly bonded to adjacent aliphatic carbon atoms in open chain configuration, the second valence of the sulfur atom being satisfied by a member of the group consisting of hydrogen and aliphatic radicals.

2. The method of inhibiting the deterioration of petroleum hydrocarbons in the presence of metals normally active to catalyze deterioration thereof, which comprises incorporating in the petroleum hydrocarbons a small amount, sum- 5. The method of inhibiting the deterioration and formation of corrosive products in viscous petroleum hydrocarbon oils which comprises incorporating therein a small amount, suflicient to retard such corrosion and formation of corrosive products, of an organic compound having an amino nitrogen atom and a divalent sulfur atom each singly bonded to adjacent aliphatic carbon atoms in open chain configuration, the second valence of the sulfur atom being satisfied by an aliphatic radical, said organic compounds being free of aromatic rings.

' 6. The method of inhibiting the deterioration and formation of corrosive products in viscous petroleum hydrocarbon oils which comprises incorporating therein a small amount, sufiicient to retard such corrosion and formation of corrosive products, of a beta-aminoethyl sulfide in which the amino nitrogen and the sulfur are in the same open chain and the second valence of 7. The method of inhibiting the deterioration and formation of corrosive products in viscous petroleum hydrocarbon oils which comprises incorporating therein a small amount, sufficient to retard such corrosion and formation of corrosive products, of a beta-aminoethyl sulfide in which the amino nitrogen and the sulfur are in the same open chain and the second valence of the sulfur is satisfied by an aliphatic radical, and the other two valences of the amino nitrogen are satisfied by members of the group consisting of hydrogen and aliphatic radicals.

8. The method of inhibiting the deterioration and formation of corrosive products in viscous petroleum hydrocarbon oils which comprises incorporating therein a small amount, sufficient to retard such corrosion and formation of corrosive products, of an open chain beta-aminoethyl sulfide in which the second valence of the sulfur is satisfied by an aliphatic radical and which sulfide is free of aromatic rings.

9. The method of inhibiting the deterioration and formation of corrosive products in viscous petroleum hydrocarbon oils which comprises incorporating therein a small amount, sufficient to figuration, the second valence of the sulfur atom being satisfied by a member of the group consisting of hydrogen and aliphatic radicals.

11. A composition of matter comprising hydrocarbons of petroleum origin having incorporated therein a small proportion of an organic compound having an amino nitrogen atom and a divalent sulfur atom each singly bonded to adjacent aliphatic carbon atoms in open chain configuration, the second valence of the sulfur atom being satisfied by an aliphatic radical.

12; A petroleum lubricating oil having incorporated therein a small proportion of an organic compound having an amino nitrogen atom and a divalent sulfur atom each singly bonded to adjacent aliphatic carbon atoms in open chain configuration, the second valence of the sulfur atom being satisfied by a member of the group consisting of hydrogen and aliphatic radicals.

13. A petroleum lubricating oil having incorporated therein a small proportion of an organic compound having an amino nitrogen atom and a divalent sulfur atom each singly bonded to adjacent aliphatic carbon atoms in open chain configuration, the second valence of the sulfur atom being satisfied by an aliphatic radical.

14. A petroleum lubricating oil having incorporated therein a small proportion of an organic compound having an amino nitrogen atom and a divalent sulfur atom singly bonded to adjacent of the group consisting of hydrogen and aliphatic radicals.

17. A petroleum lubricating oil having incorporated therein a small proportion of an open chain beta-aminoethyl sulfide in which the second valence of the sulfur is satisfied by an allphatic radical and which sulfide is free of aromatic rings. g

18. A petroleum lubricating oil having incorporated therein a small proportion of an open chain primary beta-aminoethyl sulfide in which the second valence of the siufur is satisfied by an aliphatic radical and which sulfide is free of aromatic rings.

- 19. A composition of matter comprising hydro-.

" aminoethyl) sulfide.

aliphatic carbon atoms in open chain configuraporated therein a small proportion of a betaaminoethyl sulfide in which the amino nitrogen and the sulfur are in the same open chain and the second valence of the sulfur is satisfied by an aliphatic radical, and the other two valences of'the amino nitrogen are satisfied by members 21. A composition of matter comprising hydrocarbons of petroleum origin having incorporated therein asmall proportion of bis-(beta-dicyclohexylaminoethyl) sulfide.

22. A petroleum lubricating oil having incorporated therein a small proportion of 1,6-hexamethylene di-(beta-aminoe'thyl) sulfide. I

23. A petroleum lubricating oil'having incorporated therein a small proportion of bis-(betaphenylaminoethyl) sulfide.

24. A petroleum lubricating oil having incorsufiicient to retard deterioration thereof, of bis- (beta-phenylaminoethyl) sulfide.

27. The method of inhibiting the deterioration of petroleum hydrocarbons in the presence of metals normally active to catalyze deterioration thereof, which comprises incorporating in the petroleum hydrocarbons a small amount, sufficient to retard deterioration thereof, of his- (beta-dicyclohexylaminoethyl) sulfide.

MELVIN A. DIE'I'RICH. 

